Made in USA leaf springs

[John Dorrer]

1 hour ago, DanielBoondock said:

Yes it’s D52 rated at 3500

Agree with the idea of a better constructed spring since the Dexters can fail, just wondering about changing the stiffness. A suspension is a frequency damper, shocks for lowband (to sub hertz) and springs plus ez flex puck maybe midband and higher. Pushing stiffness (higher weight rating) would increase the low cut off frequency, thus losing damping

Again this isn’t my field but I think this is what we have. The other factor is tire pressure, seems like people here tend to ride low for a less bump. Indeed here, that lowers the cutoff frequency. I prefer running at spec for efficiency and I have a hard time ignoring ratings. Possibly people having more issues are running softer pressures? Just a thought 

Unaware of any issues on the 5200 lb. Axels since Oliver switched to the 5200 lb. axels. After 5 years we are replacing shocks and having Alcan 4-leaf springs installed.

 The place that services our suspension said they noticed a slight flattening of the springs. The Alcans just arrived.

[jd1923]

You can follow the 80 PSI MAX spec on the Load Range E LT tire, the 65 PSI rating OTT prints on their DOT label (they used to print 80), or the PSI recommended by the tire manufacturer, based on actual GTW on their load/pressure tables.

I/we, most of us, follow the latter. I use any PSI over 45, less than 50, to set them all equal in that range. These numbers allow for 7,800 to 8,360 LBS GTW. On long trips, we carry max 6,600 LBS, so in this range we have spec plus a 20% safety margin. If you run at 65 or 80 PSI, you will cause internal damage to your Oliver.

Regardless of brand, LT 225/75R16 tires will all be very close to the numbers you see here. I understand new hulls to have 15" wheels, so get a table for your size. I must have posted this table 6 times now... 

 

Edited Sunday at 11:14 PM by jd1923

[Tom and Doreen]

1 hour ago, John Dorrer said:

Unaware of any issues on the 5200 lb. Axels since Oliver switched to the 5200 lb. axels. After 5 years we are replacing shocks and having Alcan 4-leaf springs installed.

 The place that services our suspension said they noticed a slight flattening of the springs. The Alcans just arrived.

That's a smart move, John, I'm glad that you're replacing them!   I was assured by the Oliver guys  at the last rally that I didn't have to worry about my springs, 2023 build with D52 axles,  because there were no problems with newer trailers with D52 axles. Well..... I have a broken spring set, passenger rear, with the remaining sets flattening.  Needless to say I'm not a 'happy camper' regarding this. I have replacements from Alcan but haven't had time or decent weather to do the repair as yet. 

[jd1923]

2 hours ago, Tom and Doreen said:

... was assured by the Oliver guys  at the last rally that I didn't have to worry about my springs, 2023 build with D52 axles,  because there were no problems with newer trailers with D52 axles.

Only because of time! The older hulls have more miles, more failed leaf springs. They are the same spring, but on a heavier axle. When I replaced ours last year, the originals were still nicely arced. Steel from China is likely not getting any better.

[John Dorrer]

13 hours ago, Tom and Doreen said:

That's a smart move, John, I'm glad that you're replacing them!   I was assured by the Oliver guys  at the last rally that I didn't have to worry about my springs, 2023 build with D52 axles,  because there were no problems with newer trailers with D52 axles. Well..... I have a broken spring set, passenger rear, with the remaining sets flattening.  Needless to say I'm not a 'happy camper' regarding this. I have replacements from Alcan but haven't had time or decent weather to do the repair as yet. 

Sorry you had that happen. Oliver was probably correct with their assessment. People driving on washboard roads, chemically treated roads, and a bad Chinese spring, can all come into play. Not much Oliver can do as they just install the Dexter suspension 

 

There is a former Oliver owner that sold their Oliver and bought a different brand. On their first trip their springs flattened. They were replaced and flattened again. They upgraded to a 5th Wheel and I believe doing an Alcan upgrade. Unfortunately, things happen.

 

We have a 3 week trip and then get them replaced June 1st.🤞

 

[DanielBoondock]

 

For other newbs I went through about half the posts on this topic so you don’t have to. I think I captured the essence

Summary

• Alcan are rated for 2k (8k total) vs 1750 (7k) for Dexter
• Spring rating depends on how well you do it (yes as an engineer this is the unvarnished truth). There’s no stock answer, they’re all approximations to the truth. Alcan is apparently known for using a well regarded approach (software I think)
• Alcan’s analysis of the 1750 Dexter is that they’re underrated for this trailer and the Alcan 2k is more appropriate 
  • One could surmise this is them ‘talking their book’, but so far the story has a ring of truth for a small shop that take their work seriously
  • Alcans specialty is springs, OTT is trailers, I think Alcan has more authority here.
  • In addition OTT has many considerations, supply chain being number one. Dexters are always available, easily replaced, come as a set with the axle, and if any owner wants an upgrade that’s available. So I think its entirely reasonable OTT is sticking with Dexter
  • But in the matter of the best spring for the application I’ll go with Alcan
• The Alcan’s therefore have a better margin in case of overload and road stress - actually they have margin, the stock at rated for max with no margin
• And it’s only a (IIRC) ~15% stiffer spring, which isn’t a great difference

For me, other than build quality the sell is that the springs provide margin without going into over engineered/overkill range. I was concerned that this is ‘bigger is better’ mentality but no, instead it’s just giving some extra room on top, which is generally a good idea. 

So I’m sold, I should be retired next year and will plan a trip to Colorado to have them installed. 

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/2/?&_rid=8320#findComment-103428

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/2/?&_rid=8320#findComment-103477

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/2/?&_rid=8320#findComment-103486

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/6/?&_rid=8320#findComment-103733

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/7/?&_rid=8320#findComment-103752

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/10/?&_rid=8320#findComment-104836

Edited 19 hours ago by DanielBoondock

[Mike and Carol]

10 hours ago, DanielBoondock said:

So I’m sold, I should be retired next year and will plan a trip to Colorado to have them installed. 

No regrets here.  Very happy with the ALCAN’s.

[CRM]

10 hours ago, DanielBoondock said:

 

For other newbs I went through about half the posts on this topic so you don’t have to. I think I captured the essence

Summary

• Alcan are rated for 2k (8k total) vs 1750 (7k) for Dexter
  
•  

In my notes I have Alcan 5 leaf rated at 2,750 and 4 leaf at 2,250. Can anyone confirm these ratings? 

[Mountainman198]

10 hours ago, DanielBoondock said:

 

For other newbs I went through about half the posts on this topic so you don’t have to. I think I captured the essence

Summary

• Alcan are rated for 2k (8k total) vs 1750 (7k) for Dexter
• Spring rating depends on how well you do it (yes as an engineer this is the unvarnished truth). There’s no stock answer, they’re all approximations to the truth. Alcan is apparently known for using a well regarded approach (software I think)
• Alcan’s analysis of the 1750 Dexter is that they’re underrated for this trailer and the Alcan 2k is more appropriate 
  • One could surmise this is them ‘talking their book’, but so far the story has a ring of truth for a small shop that take their work seriously
  • Alcans specialty is springs, OTT is trailers, I think Alcan has more authority here.
  • In addition OTT has many considerations, supply chain being number one. Dexters are always available, easily replaced, come as a set with the axle, and if any owner wants an upgrade that’s available. So I think its entirely reasonable OTT is sticking with Dexter
  • But in the matter of the best spring for the application I’ll go with Alcan
• The Alcan’s therefore have a better margin in case of overload and road stress - actually they have margin, the stock at rated for max with no margin
• And it’s only a (IIRC) ~15% stiffer spring, which isn’t a great difference

For me, other than build quality the sell is that the springs provide margin without going into over engineered/overkill range. I was concerned that this is ‘bigger is better’ mentality but no, instead it’s just giving some extra room on top, which is generally a good idea. 

So I’m sold, I should be retired next year and will plan a trip to Colorado to have them installed. 

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/2/?&_rid=8320#findComment-103428

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/2/?&_rid=8320#findComment-103477

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/2/?&_rid=8320#findComment-103486

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/6/?&_rid=8320#findComment-103733

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/7/?&_rid=8320#findComment-103752

https://olivertraveltrailers.com/forums/topic/9996-made-in-usa-leaf-springs/page/10/?&_rid=8320#findComment-104836

Couple comments from your observations. Alcan weight rating (capacity) is 2,750 for 5 leaf and 2,250 for 4 leaf.  Weight rating is the designed weight at which a spring pack fails.  As the same top four leafs are utilized in both 4 and 5 leaf versions, spring rate (a.k.a. “Ride”) remains largely the same even though weight rating is different. Spring rate is amount of weight required to deflect spring 1” when at ride height.

While unable to locate any documentation from Dexter as to “buffer” capacity for their springs I was able to locate documentation from LCI (Lippert) which states that there should be a 20% weight capacity buffer between the total weight capacity of a set of their leaf springs and the curb weight of a fully loaded trailer. Reason stated for maintaining this buffer is to accommodate travel over uneven roads, curbs, potholes, dips and other occurrences which could temporarily increase the actual weight on a spring pack. 7,000x .8= 5,600. My trailer weighs 6,200 ready to travel. 
 

I chose the 5 leaf Alcans for my trailer and have been quite happy with their performance. I know a few others have chosen the 4 leaf versions and they seem happy with their choice as well. Either choice is a huge upgrade from the RV industry standard (dexter).

Edited 9 hours ago by Mountainman198

[DanielBoondock]

 

5 minutes ago, Mountainman198 said:

Alcan weight rating (capacity) is 2,750 for 5 leaf and 2,250 for 4 leaf.

Great correction thanks, the post I got that from was misstating it

 

6 minutes ago, Mountainman198 said:

As the same top four leafs are utilized in both 4 and 5 leaf versions, spring rate (a.k.a. “Ride”) remains largely the same even though weight rating is different. Spring rate is amount of weight required to deflect spring 1” when at ride height ... LCI (Lippert) which states that there should be a 20% weight capacity buffer between the total weight capacity of a set of their leaf springs and the curb weight of a fully loaded trailer. Reason stated for maintaining this buffer is to accommodate travel over uneven roads, curbs, potholes, dips and other occurrences which could temporarily increase the actual weight on a spring pack. 7,000x .8= 5,600.

Bingo, I talked about this above but kept it short so the post wouldn't get too confusing. Buffer is what I call margin, and exactly I mentioned that it's there for overloading (which happens) and impulse load (road conditions). As for the relationship between static and dynamic load, AI says (asking for cars as the models will be deeper on that topic, but its obviously the same)

 

Quote

 

Yes, the static load rating for car springs must account for impulse loads (shock loads) to ensure the spring does not fail, deform, or cause the suspension to bottom out. 

While a static load refers specifically to the weight of the vehicle when parked, the designed "static load capacity" used in selecting or engineering a spring must anticipate the maximum potential dynamic forces. 

Here is how impulse loads (driving over bumps, potholes, or hard braking) are accounted for:

• Safety Factors/Factor of Safety: Engineers typically use a safety factor of 2–4 times the static load to account for sudden impacts and shock loading.
• Maximum Operating Load: The spring must be able to handle "solid height" (maximum compression) without permanent deformation (taking a set). This means the static design must accommodate the maximum deflection caused by an impulse load.
• Dynamic Load Factors: Springs are designed to handle "dynamic loads" (changing loads), which represent the combination of the vehicle weight and the amplified forces from road conditions (which can exceed 2G). 

If a car spring is selected based solely on the static, parked weight of the vehicle, it will likely be underspecified and prone to failure when subjected to driving, vibration, and impact loads.

 

This lends me to think that the five spring, which I think Alcan suggests here, is the better choice. That's a 11k static load rating compared to 9k for the four spring. The axles are rated at 10k, but as the brunt of the dynamic force is taken by the sprung suspension, so being a bit overspec there isn't bad. 

 

So, five springs here I come ...

 

tl/dr

As for the counterargument that it will transmit more road shock and vibration, the true test is measuring it. Before/after vibration tests. Fortunately this is easy using your phone, Vibration Meter stores history and outputs CSV. Test procedure would be to

• Securely attach the phone to a hard surface in the trailer. 
  • 3M Velcro Command Strips to the floor 
• Start measuring and drive
  • Synchronizing before and after should be done ideally. 
  • Simplest is probably a 'clapboard marker' by just noting the time you pass a GPS coordinate or landmark
• Or don't be so precious, simply measure RMS

I'll do this test by measuring on the same road(s) before/after

 

[dewdev]

@DanielBoondock

I would be interested in finding out what your vibration road test results will be. Please let us all know.

[theOrca]

29 minutes ago, DanielBoondock said:

 

Great correction thanks, the post I got that from was misstating it

 

 

tl/dr

As for the counterargument that it will transmit more road shock and vibration, the true test is measuring it. Before/after vibration tests. Fortunately this is easy using your phone, Vibration Meter stores history and outputs CSV. Test procedure would be to

• Securely attach the phone to a hard surface in the trailer. 
  • 3M Velcro Command Strips to the floor 
• Start measuring and drive
  • Synchronizing before and after should be done ideally. 
  • Simplest is probably a 'clapboard marker' by just noting the time you pass a GPS coordinate or landmark
• Or don't be so precious, simply measure RMS

I'll do this test by measuring on the same road(s) before/after

 

Oh Lord but I love this group. On the way to have my new suspension fitted, I will have my newly programmed iPhone taped to the floor on the way to and from. Will post the data after.  (Probably 4 weeks out...)

[DanielBoondock]

6 hours ago, theOrca said:

Oh Lord but I love this group. On the way to have my new suspension fitted, I will have my newly programmed iPhone taped to the floor on the way to and from. Will post the data after.  (Probably 4 weeks out...)

My working life was in measurement equipment for NASA, three letter agencies and other spooky groups 😅 

It would be interesting to see it broken in frequency bands. For whatever reason I suspect we’d see a response shift. Basically the suspension is a filter and we’re changing the parameters

Anyhow I found a top drawer shop locally that specializes in trailer suspension so I’ll do it here this year, pending your data. I recommend a low hard surface like the floor to capture the from suspension output. Vibration might increase further up, and we want to avoid induced response from dirtying the signal. Might not matter either and we’re looking for order of magnitude anyhow but will be interesting 

Best of all is taping it to the frame directly if you’re comfortable with that